Mashed allen key socket - now what?

[swee'pea99]

Just got an n+1 off fleabay, and the first thing I need to do is get the cranks off, but I've run into a problem. The crank 'caps', or whatever you call them, seem pretty much seized on, and the allen key holes have been rounded off by someone trying to shift them:

A bit of googling came up with a suggestion of whacking a torx fitting in, then using that to unscrew. So I tried that. But the stickiness of the stick was too much for it, and I've succeeded only in scraping a little more metal off the walls of the hole. So I'm a bit stumped now. Just wondered if anyone hereabouts might have any suggestions?

 

[Profpointy]

it seems slightly domed so you could saw a slot in it and use a big screwdriver. Obviously try and soak the thread in oil. at a pinch you mught be able to just lever it off, as it is just a dust cap, but that risks damaging the internal threads on the cranks - which the crank remover presumably needs

 

[Falco Frank]

Using a torx would of been my suggestion too but with lots pf releasing fluid used too, halford sell a good stuff called shock and unlock but anything is better than nothing, the longer soaking the better. Since it should just be a thin cap on the outside, next might be drilling two holes opposite each other and using something like circlip pliers. Sadly , i can see the cap outer not being too stong and giving away, but at least leaving a stub for you to be able to get at.
Drilling it out might be a final option. Good luck.

 

[Deleted member 35268]

I share your pain, I have had a similar issue but with the allen key inside the front forks that attach the brakes (and the mudguards). I chewed it up.

My issue is now resolved, I bent the guards off, and managed to spin the brakes and free the whole lot. Only took 6 months.

 

[Hacienda71]

I would probably cut it out with a Dremel. This however would probably not be the best course of action.

 

[swee'pea99]

Thanks all. I think at the moment my preferred Plan A is to leave it PlusGas'd for a couple of hours, see if that helps (I've never know it to, TBH, but I guess it can't hurt), then try the torx thing again. Then when that doesn't work, I think I'm going to go with profpointy and see if I can't hacksaw a slot in it big enough to take a big screwdriver. I don't hold out great hopes for this, tho', as the dome is slight, and I can't see myself getting a slot deep enough to offer any real purchase. Plan C comes off another bit of googling - drill a hole close to the perimeter, then use that as an 'anchor point' for a screwdriver, then bash it with a hammer in a ccw direction. Plan D is available within walking distance, and comes in handy pint size measures...

 

[sight-pin]

Would it be possible to drill it out and then remove the remainder with mole grips once the cap is removed?

 

[Profpointy]

another thought on "cutting a slot" - a junior hacksaw blade or file might fit in the allen socket (if drilled out) so you can cut the screwdriver slot out sidewards as it were

There's a lot to be said for cheap plastic dust caps which just be prised off!

 

[swee'pea99]

Would it be possible to drill it out and then remove the remainder with mole grips once the cap is removed?

Not sure I quite understand this. Particularly the 'once cap is removed' bit. It's only the cap-removal that's the issue, at least at the moment. The main issue being getting the cap out in such a way as to not damage the threading inside the crank itself. which is kind of crucial for fitting a crank removal tool.

 

[swee'pea99]

another thought on "cutting a slot" - a junior hacksaw blade or file might fit in the allen socket (if drilled out) so you can cut the screwdriver slot out sidewards as it were

Interesting. I don't think I have a metal drill big enough to make a hole big enough to take even a junior hacksaw blade...but I guess I could buy one...

 

[Profpointy]

Interesting. I don't think I have a metal drill big enough to make a hole big enough to take even a junior hacksaw blade...but I guess I could buy one...

yet another idea - araldite in the closest fit torx or allen driver you can jam in. leave overnight to set properly, and clean the metal properly first of course.

 

[swee'pea99]

I'm going to go out & walk the dog for a bit now, to give the PlusGas at least half a chance. Otherwise I know I'll just get frustrated and keep going at it in more & more inane ways till I do some real damage.

 

[swee'pea99]

yet another idea - araldite in the closest fit torx or allen driver you can jam in. leave overnight to set properly, and clean the metal properly first of course.

Sounds good. Worth a try, surely...

 

[sight-pin]

Not sure I quite understand this. Particularly the 'once cap is removed' bit. It's only the cap-removal that's the issue, at least at the moment. The main issue being getting the cap out in such a way as to not damage the threading inside the crank itself. which is kind of crucial for fitting a crank removal tool.

I meant drill the head off the screw to remove the cap, then that should leave a bit of thread sticking up you could grab with a pair of mole grips...no! would that not work? I didn't mean drill to deep to be able damage the thread.

 

[Profpointy]

I meant drill the head off the screw to remove the cap, then that should leave a bit of thread sticking up you could grab with a pair of mole grips...no! would that not work? I didn't mean drill to deep to be able damage the thread.

the threaded bit is internal thread inside the cranks. There's no thread sticking up here. The allen socket is part of the cap so you can (in theory) undo it, not a an allen screw into the cap.